A flame sensor is designed to detect the presence of a flame or fire.
- If flame sensor use IR sensor to detect flame,Infrared (IR) flame detectors monitor the infrared spectral band for specific patterns given off by hot gases.
- Typically sensitive to wavelengths around 4.4 micrometers, which is a spectral characteristic peak of hot carbon dioxide as is produced in a fire.
- The usual response time of an IR detector is 3 to 5 seconds.
- The flame sensor is very sensitive to IR wavelength at 760 nm ~ 1100 nm light.
- It can give two output
1.Analog: Time output voltage signal on the thermal resistance.
2.Digital: When the temperature reaches a certain threshold, the output high and low signal threshold adjustable via potentiometer.
Hardware Required

- Fire Sensor.
- ADC 0804.
- 8051 MicroController.
Pin Diagram
- VCC:Positive voltage input: 5v for analog 3.3v for Digital,
- A0: Analog Output,
- D0: Digital Output,
- GND: GND.
Circuit Analog

Circuit Digital
